Insulated fringed branch for artificial trees and method



Oct. 2, 1962 s. P. CRANE 3,056,223

INSULATED FRINGED BRANCH FOR ARTIFICIAL TREES AND METHOD Filed June 2'7, 1960 E 2 SLIT ALUMINUM F'OIL ADHESIVE P0 LYETHYLENE IN V EN TOR. 5007091 F Gran e MIME A TTOR/VEY hire 3,056,223 Patented (let. 2, 1952 3,tl56,223 INSULATED FRENGED BRANCH FOR ARTIFitIliAlL TREEfi AND METHOD Samuel P. Crane, 1 Warwick Road, Great Neck, NY. Filed June 27, 196i Ser. No. 38,941 14- (Ilaims. (Ci. 41-15) This invention relates to the foil fringe material such as is used in making branches for artificial Christmas trees, as Well as to the branches and the method of making the fringe and the branches.

Defective Wiring to the electric lights frequently strung on such trees, gives rise to the danger of the occurrence of a short circuit permitting current to pass through the uncut connecting part of the metallic foil fringe throughout the length of the branch, with consequent likelihood of injury by electric shock to one touching the branch or perhaps other branches which may be in electric contact with each other.

The present invention is directed to the insulation electrically of the foil fringe between adjacent relatively short sections thereof throughout the length of the branch covered by the fringe, whereby a short circuit, if it occurs, is confined to such short section and the shock hazard is so greatly decreased as to be substantially eliminated.

The invention contemplates the provision of a foil fringe made up of longitudinally spaced apart sections of predetermined length held together by a backing strip or sheet of electrically non-conductive flexible and stretchable material such as polyethylene, whereby current accidentally applied to one section, is confined to that section and does not enter any other section of the same foil fringe.

The invention further contemplates the provision of a simple method of making the sectional fringe by permanently stretching the insulating backing therefor, and thereby separating the sections mechanically and electrically.

The various objects of the invention will be clear from the description which follows and from the drawings, in which FIG. 1 is an elevational view of part of a length of foil fringe as it appears assembled to its insulating backing strip and prior to the separation of the sections thereof.

FIG. 2 is a side elevation view thereof.

FIG. 3 is a view of the assembled fringe unit similar to FIG. 1 but showing the sections separated preparatory to winding the fringe into helical form.

FIG. 4 is a view of the edge of the fringe unit of FIG. 3.

FIG. 5 is a fragmentary elevational view of an imitation tree branch showing the fringe unit wound into a helix of large pitch on a support of relatively small diameter, the fringe fingers of the lower turns being cut off to expose the gaps in the uncut connecting part of the fringe.

FIG. 6 is a view similar to FIG. 3 of a modified fringe unit showing a relatively wide insulating backing strip and also showing in dash-dot lines how the strip may be moved up to overlie the fingers to a substantial extent before it is attached to the foil fringe, as when it is to be wound in a helix of large pitch on a support of relatively large diameter.

FIG. 7 is a fragmentary elevational View of a branch with the greater part of each of the fingers removed, showing the fringe unit of FIG. 6 wound on a temporary support in overlapping position to form a self-supporting insulating tube with the fringe fingers projecting therefrom.

FIG. 8 is a diagrammatic view of a machine for assembling the foil and strip and for permanently stretching the backing strip.

FIG. 9 is a top plan View of the stretching part of the machine.

FIG. 10 shows another form of the stretching machine.

In carrying out the invention, the foil fringe 10 is preferably formed of aluminum foil of the desired width, and may be colored on one side or back with colored paper part way or entirely across its width. Non-severing cuts 11 are made in a well known manner to extend from one side edge 12 of the foil strip toward the other edge 13, the cuts terminating along a line in transverse spaced relation to the edge 13 to leave an uncut edge portion 14 connecting the inner ends of the resulting fringe fingers 15. In the present invention, the foil strip is cut during the fringe forming operation so that it can readily and economically be ruptured into electrically independent sections which are longitudinally separated and insulated from each other.

In one form of the invention, the cuts 11 are separated at desired intervals with longer cuts 16 extending quite close to the edge 13, and almost, but not quite, severing the foil strip. Such cuts to weaken the otherwise uncut finger-connecting part 14- of the fringe strip to such an extent that the strip may readily be torn apart at the uncut part 14 along a line forming an extension. of the cut 16, as by tensioning the strip in the direction of the arrows of FIG. 1. In another form of the invention, all cuts 11 are of substantially the same length. The fringe is not ruptured until it is suitably backed as by the insulating backing strip 18 which is bonded to the uncut edge part 14 as by the adhesive layer 19 which may be a hot melt, or of a solvent type or a quick tack adhesive. Or the insulating strip may be heat sealed or welded to the metallic fringe or extruded directly thereon while hot in a manner well known in the extrusion art. The backing strip is made of a suitable flexible and elastic, non-conducting plastic suitably colored if desired, and capable of being set to retain permanently its increased length after stretching, such as for example, polyethylene. When the attached backing strip is tensioned and thereby stretched, only enough stress is put thereon to complete the rupture of the foil strip at each cut 16, or at a selected cut 11, thereby to separate the fringe strip into sections separated by the gaps 17 therebetween where the breaks occurred. The strip 18 thereby joins the sections of fringe together and insulates them from each other.

The width of the backing strip 18 may be considerably varied depending on the density of the fringe desired, the type of support for the foil, the resiliency of the fingers and other factors determining the appearance of the wound branch and the likelihood of the fingers of the various sections coming into electrical contact with each other. The density of the fringe fingers in turn depends on the diameter of the permanent support as 20 of FIG. 5, or as the temporary mandrel or support 21 of FIG. 7 on which the combined fringe unit is to be wound to form the imitation branch, also on the pitch of the helix along which the unit is wound and on the number of layers or plies of the backing strip it is desired to build up on the temporary or permanent support for the unit, as will be explained in more detail hereinafter. The backing strip may extend a short distance inwardly from the side edge 13 of the fringe, past the inner ends of the cuts 11, or it may extend a substantial distance inwardly as shown by the dash-dot lines of FIG. 6. In either case, the strip 18 preferably projects transversely and outwardly past the side edge 13 of the foil fringe.

As seen in FIG. 8 showing a machine capable of carrying out the method above described, adhesive is applied by the roller 22 to the connecting part 14 only of the foil strip 10, the roller being narrow enough for that purpose and receiving adhesive from a roller rotating in the gum box 23. The fringe strip 10 may be fed to the roller 22 directly from the fringing machine or from a roll of fringe. Rollers 2.4, 25 advance the strip without coming into contact with the adhesive, the foil being suitably supported during its advance. The

plastic backing strip 18 is fed from the roll 26 thereof in between the rollers 27, 28 where it is pressed against the adhesive 19 on the fringe part 14 and adheres thereto.

To rupture the fringe only at each long cut 16, advance of the combined foil and backing strips is resisted by one of the advancing rollers as 29 which cooperates with the roller 34) for that purpose and is mounted on the shaft 31. Said shaft carries a suitable rotatable brake member 32 which engages the fixed brake member 33 and constitutes a suitable drag resisting rotation of the rollers 29 and 30 which are urged to rotate by the moving strip. However, the roller 34, which is driven by a motor, coacts with the roller 35 to advance the forward part of the combined strip, and exerts such tension on the strip as to complete the severing of the foil fringe at that long cut 16 which has just passed the roller 29. At the same time, the rollers 34 and 35 tension and stretch the backing strip. In order to prevent the foil strip from being torn at a cut 11 when cuts 16 are provided for such tearing, the slip clutch 36 on the shaft for the roller is provided. The clutch prevents initial tension of too great an amount from being exerted on the fringe strip, by slipping under such excessive tension as might sever the foil strip at the fingers other than at the cuts 16. To set and permanently maintain the backing strip in its stretched and increased length, a suitable heater as 37 is arranged to warm said strip and to relieve the internal stresses generated therein during the stretching operation. In this manner, the fringe strip is permanently separated into the sections 38 having the gaps I7 therebetween and joined only by the permanently stretched polyethylene backing strip at the uncut edge part 14, as shown in FIGS. 3, 4 and 6. The thus sectioned strip unit may be wound up into the coil or roll 39 or it may be fed to a suitable winding machine for winding it on a rod as 20 (FIG. to form the branch 40. Or the sectioned unit may be wound on a removable mandrel 21 (FIG. 7) to be formed into a self-supporting tubular branch 42.

In the form of the apparatus shown in FIG. 10, which operates on a foil strip having only cuts 11 of uniform length, the brake 32, 33 is omitted and is replaced by the trough 45 extending across the width of the backing strip and serving as part of the means to stretch the backing strip sufficiently to rupture the foil fringe at the point where the backing strip is stretched. The fixed trough coacts with a pair of vertically reciprocating holding fingers 46, 47 preferably spaced apart slightly more than the width of a fringe finger Said holding fingers move downwardly and press the combined strip against the side flanges of the trough. Thereafter, the stretching finger 48, which has a dull or rounded edge inclined upwardly and forwardly, moves down between the holding fingers and presses the combined strip downwardly into the recess of the trough 45. The backing strip being elastic, that part thereof between the holding fingers stretches, but does not rupture. However, the foil fringe does break under the tearing action of the inclined end edge of the stretching finger 43 which serves as a combined shearing and tearing tool, by engaging the foil strip first near the end of a cut 11 and then moving across the uncut part of the fringe as it moves downwardly. When the holding and stretching fingers move upwardly, the strip is released and forwarded by the rollers 34, 35 and the stretched part flattened, the operation being repeated at the desired intervals.

The holding and stretching fingers are operated by the spring-retracted armatures of suitable solenoids as St), 51 respectively, to which the circuit is closed at intervals by suitable switches as by the rotatable arcuate conductors 52, 53 carried by the roller 29, and brushes 54, 55 respectively coacting with the conductors. The switch contact or conductor 52 is shorter than the contact or conductor 53 so that the armature for the holding fingers 46, 47 moves down on to the work before the stretching finger moves down. The holding fingers stay down on the combined foil fringe and backing strip until the stretching and foil rupturing operation has been completed and until the stretching finger has been retracted by the spring acting on the armature for said finger. Thereafter, the spring for the armature of the solenoid 50 becomes effective to raise the holding fingers and to free the work for further advance thereof by the roller 34.

Said roller 34 is rotated by the same means as in 'FIG. 9 to permit the arcuate rotating contact members 52 and 53 to close the circuits to and to energize the solenoids 50 and 51 respectively, for the required time interval only, just sufficient to enable the fingers to perform the stretching and tearing operations. During the operation of said fingers, the Work remains stationary, and the roller 34 is permitted to rotate and to slip on the work to the extent necessary to allow the contact members to engage and to pass the corresponding brush members 54, 55. The slip clutch 36 also permits said roller to take up the slack in the combined foil and backing strip, resulting from the operation of the fingers.

As will be seen from FIGS. 3 and 6, the amount of overlap of the backing strip on the foil fringe may be considerably varied and depends on a number of factors which will now be discussed. The extent of the inward overlap of the backing strip on the fringe should be such that the upper edge of the backing strip as 43 does not encroach, when wound into a helix to form a branch, on the inner ends of the fingers, though it may overlap the uncut part 14 partly or entirely.

Where the pitch of the helix along which the upper edge 43 extends, is large as in FIG. 5, and the backing strip is narrow, a rod as Ztl' of relatively small diameter may be used as the support without danger of the fingers of the various sections coming into contact with each other and becoming electrically connected. In FIG. 5, the backing strip could indeed be widened upward to a considerable extent without interfering with the fingers of the turn above. It could also be widened downwardly if a multi-ply thickness of ply of the wound backing strip is desirable.

However, when the pitch of the helical curve becomes rather large for economy or to attain considerable spacing apart of the fringe fingers, it is preferable to employ a support or mandrel of larger diameter as shown in FIG. 7. On reducing the pitch, the permissible amount of in Ward overlap of the backing strip on the fingers is lessened, but the amount of overlap of each turn on the previous turn is increased in area. The pitch can be selected to attain as many plies of material as is desired to form a self-supporting tube and a complete fringe-carrying branch with insulated sections on the removal of the temporary support or mandrel 21, provided that the pitch is not reduced to the extent which might carry the fringe fingers of different sections into contact with each other.

It should now be clear that the gaps 17 between the sections 38 confine any short circuit to the particular section affected and that the insulated backing performs the functions of an insulating connector for the sections and a reinforcing tubular supporting member for the fringe especially when wound with a short pitch and overlapped.

While certain specific forms of the invention have herein been shown and described, various obvious changes may be made therein without departing from the spirit of the invention defined by the appended claims.

I claim:

1. A fringe strip comprising a plurality of longitudinally spaced apart metallic fringe sections each having an uncut edge portion and having fingers extending transversely from the edge portion, and a supporting strip of smooth flexible insulating sheet material secured only to a limited width of the edge portions of the sections and arranged to bridge the gaps between said edge portions thereby to maintain the sections out of contact with each other.

2. The fringe strip of claim 1, the supporting strip being wider than the uncut edge portions of the sections and narrower than the material of the sections and extending transversely outwardly beyond said edge portions.

3. The method of making an insulated fringed branch for a Christmas tree comprising weakening a metallic foil strip by making cuts at intervals completely through the strip and almost but not quite completely across the strip while cutting fringe fingers in the strip, then securing a stretchable insulating strip to the foil strip at the bases of the fingers and across the weakening cuts, stretching the insulating strip sufficiently to rupture and to create gaps in the fringe strip at the weakening cuts, and winding the stretched strip into helical form.

4. The method of making an imitation of a Christmas tree branch comprising making a sectional metallic fringe in which the adjacent sections are electrically insulated from each other, by first cutting metallic foil into fringe fingers to leave an uncut finger-connecting part on the foil at the bases of the fingers while making a cut longer than the finger-forming cuts at selected intervals to extend into the otherwise uncut part of the fringed foil and thereby to weaken the foil at said longer cuts, then adhesively securing a strip of stretchable, flexible, insulating material to the uncut connecting part of the fringe at the bases of the fingers and to extend across the longer cuts, permanently stretching the strip sufficiently to rupture the uncut part of the fringe at the longer cuts and to separate the fringe into sections joined only by the strip and otherwise free throughout the width thereof, and winding the stretched strip into helical form.

5. The method of making a metallic fringe having conducting sections insulated from each other, each section having an uncut continuous relatively narrow finger-connecting part and cut fingers projecting from such part, comprising attaching an insulating strip to the finger-connecting part of the fringe, and then stretching the strip at spaced intervals thereof sufficiently to rupture the connecting part of the fringe at such intervals and to separate the fringe into spaced apart sections.

6. The fringe making method of claim 5, and setting the stretched parts of the strip by heat and pressure to maintain the strip permanently stretched.

7. A safety metallic fringe for a Christmas tree branch comprising adjacent foil fringe fingers completely apart from each other and a continuous flexible plastic strip of insulating material connecting only the bases of said fingers and thereby forming the connecting means for the fingers incapable of transmitting current between adjacent fingers which are apart, said strip being adapted to be wound helically to spread further apart those parts of the fingers which are free of the strip.

8. A fringe strip for winding about a support, comprising a plurality of metallic fringe members, each completely out of contact with the adjacent members, and means for maintaining the members out of electrical contact with each other comprising a continuous strip of flexible insulating sheet material attached to the bases of the members and of lesser width than the Width of the members, the members being free of each other and unsupported except at said bases.

9. The fringe strip of claim 8, each of the fringe members having a plurality of transverse continuous cuts completely therethrough forming fringe fingers, and having an uncut edge portion, the supporting strip being of a stretchable plastic material and being attached only to the edge portions.

10. A fringe-holding branch for an artificial tree comprising an elongated support and a plurality of spaced apart metallic fringe sections, each section having a marginal fringe finger free of the adjacent marginal finger of the adjacent section throughout the entire length of the finger and out of electrical contact with said adjacent finger, the bases of the sections being wound helically around the support and each section being insulated from the adjacent sections by the spaces between marginal fingers of the sections.

11. The branch of claim 10, the support being tubular and comprising a continuous initially independent strip of flexible insulating material secured to the fringe sections adjacent a side edge of each section and maintaining and securing together the sections in longitudinal spaced relation and insulated from each other, the strip bridging the spaces between sections.

12. A fringe-holding branch for artificial trees, comprising a sectional fringe of electrical conducting material having gaps throughout the entire width thereof at selected intervals therein, and a continuous backing strip of flexible insulating sheet material narrower than the fringe bridging the gaps and adhesively secured to and overlapping an edge portion of the fringe, the fringe and the backing strip constituting a combined stem and leaf unit helically wound in a plurality of turns to form a self-supporting tube constituting the stem of the branch with fringe fingers projecting therefrom and constituting the leaves of the branch.

13. The method of making a metallic fringe comprising weakening at intervals the normally uncut fingerconnecting part of a fringe having such part and having otherwise free completely cut fingers projecting from such part, the weakening being performed by spaced apart cuts longer than and parallel to the fingenforming cuts, adhering an insulating strip to and adjacent the connecting part of the fringe, and then stretching the strip sufiiciently to rupture said part at. such intervals and to separate the fringe into sections free of each other along substantially the entire width thereof except where joined by said strip, and insulating the sections from each other by creating spaces between the sections.

14. The method of making an insulated fringed branch for a Christmas tree comprising weakening at intervals the normally uncut finger-connecting part of a fringe having such part and having otherwise free completely cut fingers projecting from such part, the weakening being performed by spaced apart cuts longer than and parallel to the finger-forming cuts, adhering an insulating strip to and adjacent the connecting part of the fringe, and then stretching the strip sufficiently to rupture said part at such intervals and to separate the fringe into sections free of each other along substantially the entire width thereof except where joined by said strip, insulating the sections from each other by creating space between the sections, winding the strip helically, and overlapping the strip on itself during the winding thereof to form a self-supporting tube with the fringe sections projecting therefrom.

References Cited in the file of this patent UNITED STATES PATENTS 2,020,928 Asnes NOV. 12, 1935 2,639,532 SeeWald May 26, 1953 2,735,426 Claydon Feb. 21, 1956 2,889,650 Hankus June 9, 1959 

